mmc: core: Introduce host claiming by context

Currently the host can be claimed by a task.  Change this so that the host
can be claimed by a context that may or may not be a task.  This provides
for the host to be claimed by a block driver queue to support blk-mq, while
maintaining compatibility with the existing use of mmc_claim_host().

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index 36217ad..8d77ddc 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -1911,14 +1911,14 @@ static void mmc_detect(struct mmc_host *host)
 {
 	int err;
 
-	mmc_get_card(host->card);
+	mmc_get_card(host->card, NULL);
 
 	/*
 	 * Just check if our card has been removed.
 	 */
 	err = _mmc_detect_card_removed(host);
 
-	mmc_put_card(host->card);
+	mmc_put_card(host->card, NULL);
 
 	if (err) {
 		mmc_remove(host);